1. Field of the Invention
The invention relates to wheel covers for motor vehicles. More specifically, the invention relates to wheel covers capable of withstanding environments of high temperatures.
2. Description of the Related Art
Wheel covers are aesthetic devices used to decorate unfinished wheels, i.e., steel wheels. The finishes of these wheel covers vary widely. Some are designed to be painted while others are designed to be plated with chrome. Other variations of the wheel cover designs include covering the lug nuts, capping the lug nuts or using decorative lug nuts. The type of finish that is utilized by a wheel cover is dependent upon the material used to manufacture or fabricate the wheel cover. Some materials that have a greater heat resistance are limited in the types of finishes that may be applied thereto.
In order that the wheel cover remain a decorative element, it must be secured to the wheel in some fashion. One method for securing a wheel cover to a wheel is by using the same lug nuts that secure the wheel to the wheel hub to secure the wheel cover to the wheel. A problem with using the lug nuts and lug studs to secure the wheel cover to the wheel is the transfer of heat generated by the brakes through the hub and lug nuts to the wheel cover. The heat is so extreme that it can compromise the integrity of the wheel cover. In some situations, it may even melt the wheel cover rendering it useless in its design to be an aesthetic component of the motor vehicle.
In related art, U.S. Pat. No 5,401,079, issued to Rooney on Mar. 28, 1995, discloses an attempt that was made to thermally isolate a plastic piece secured to the wheel hub from the wheel hub. While this reference does not disclose a wheel cover, it does disclose a plastic wheel secured to a wheel hub. Because the thermal energy of the wheel hub can become so great, the plastic wheel must have protection therefrom.
U.S. Pat. No. 5,401,079 discloses the plastic wheel protected by sleeves that extend through holes in the plastic wheel that receive the lug studs therethrough. The sleeves are substantially cylindrical in shape and are fabricated from steel. The sleeves have grooves extending around the outside thereof to provide a mechanical lock, either by heating the plastic to a point after which it flows into the grooves or by molding the sleeves into the plastic at the outset. Because there is no bonding between the plastic wheel and the metal sleeves, the locking is purely mechanical.
Another disadvantage associated with the wheel assembly disclosed in U.S. Pat. No. 5,401,079 is the amount of material required to manufacture the disc. More specifically, the metal sleeves require a substantial amount of plastic abutting thereagainst to provide the support necessary to have the metal sleeve maintain its form. This adds weight to the overall design resulting in lower fuel economies.